NCLEX RN Oxygen Therapy Practice
Exam 100 Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026
1. A nurse is caring for a client receiving oxygen through a nasal cannula.
Which assessment finding requires immediate intervention?
A. Oxygen saturation of 94%
B. Respiratory rate of 20/min
C. Dry nasal mucosa
D. Oxygen tubing disconnected from the flowmeter
Answer: D. Oxygen tubing disconnected from the flowmeter
Rationale: A disconnected oxygen system can abruptly interrupt oxygen
delivery and cause hypoxemia. The nurse should reconnect the tubing and
assess the client's respiratory status immediately.
2. Which oxygen-delivery device provides the most precise concentration of
oxygen?
A. Nasal cannula
B. Simple face mask
C. Venturi mask
D. Nonrebreather mask
Answer: C. Venturi mask
Rationale: A Venturi mask delivers a precise, controlled fraction of inspired
oxygen and is particularly useful for clients who require carefully regulated
oxygen concentrations.
,3. A client is prescribed oxygen at 2 L/min by nasal cannula. What
approximate FiO₂ does the client receive?
A. 21%
B. 24%
C. 28%
D. 40%
Answer: C. 28%
Rationale: A nasal cannula generally increases FiO₂ by approximately 4% per
liter/minute. At 2 L/min, the estimated FiO₂ is about 28%.
4. Which oxygen-delivery device is most appropriate for a client who requires
a high concentration of oxygen but is breathing spontaneously?
A. Nasal cannula
B. Simple face mask
C. Nonrebreather mask
D. Venturi mask at 24%
Answer: C. Nonrebreather mask
Rationale: A nonrebreather mask can deliver a very high concentration of
oxygen, often approximately 60%–95%, when the reservoir bag remains
inflated and the mask fits properly.
5. The nurse applies a nonrebreather mask to a client. Which finding indicates
correct application?
A. The reservoir bag completely collapses during inspiration
B. The reservoir bag remains partially inflated during inspiration
C. Oxygen flow is set at 1 L/min
D. The exhaled air is directed into the reservoir bag
Answer: B. The reservoir bag remains partially inflated during inspiration
,Rationale: The reservoir bag should remain partially inflated during
inspiration to ensure the client receives the intended high oxygen
concentration.
6. Which oxygen flow rate is generally appropriate for a simple face mask?
A. 1–2 L/min
B. 3–4 L/min
C. 5–10 L/min
D. 15–20 L/min
Answer: C. 5–10 L/min
Rationale: A simple face mask should generally be used at 5–10 L/min. Lower
flows may allow carbon dioxide to accumulate inside the mask.
7. A client with chronic CO₂ retention requires controlled oxygen therapy.
Which device should the nurse anticipate?
A. Nonrebreather mask
B. Venturi mask
C. Partial rebreather mask
D. Face tent
Answer: B. Venturi mask
Rationale: A Venturi mask allows precise control of oxygen concentration,
making it useful for clients at risk for oxygen-induced hypercapnia, such as
some clients with COPD.
8. Before administering oxygen, what is the nurse's priority action?
A. Apply petroleum jelly to the client's nares
B. Assess the client's respiratory status
C. Place the client in a supine position
D. Increase the oxygen flow rate to 10 L/min
, Answer: B. Assess the client's respiratory status
Rationale: The nurse should assess respiratory rate, effort, breath sounds,
oxygen saturation, and overall clinical status before and during oxygen
therapy.
9. Which position usually promotes optimal lung expansion in a client
experiencing dyspnea?
A. Supine
B. Trendelenburg
C. High-Fowler's
D. Prone with legs elevated
Answer: C. High-Fowler's
Rationale: High-Fowler's positioning promotes diaphragmatic expansion and
reduces pressure from abdominal organs on the diaphragm, facilitating
ventilation.
10. Which instruction should the nurse give a client receiving oxygen at
home?
A. "Smoking is acceptable if you turn off the oxygen first."
B. "Keep oxygen equipment away from flames and heat sources."
C. "Use petroleum jelly inside your nose for dryness."
D. "Store oxygen cylinders next to a radiator."
Answer: B. "Keep oxygen equipment away from flames and heat sources."
Rationale: Oxygen supports combustion. Clients should avoid smoking, open
flames, sparks, and heat sources around oxygen equipment.
11. Which product should the nurse recommend for nasal dryness in a client
receiving oxygen?
Exam 100 Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026
1. A nurse is caring for a client receiving oxygen through a nasal cannula.
Which assessment finding requires immediate intervention?
A. Oxygen saturation of 94%
B. Respiratory rate of 20/min
C. Dry nasal mucosa
D. Oxygen tubing disconnected from the flowmeter
Answer: D. Oxygen tubing disconnected from the flowmeter
Rationale: A disconnected oxygen system can abruptly interrupt oxygen
delivery and cause hypoxemia. The nurse should reconnect the tubing and
assess the client's respiratory status immediately.
2. Which oxygen-delivery device provides the most precise concentration of
oxygen?
A. Nasal cannula
B. Simple face mask
C. Venturi mask
D. Nonrebreather mask
Answer: C. Venturi mask
Rationale: A Venturi mask delivers a precise, controlled fraction of inspired
oxygen and is particularly useful for clients who require carefully regulated
oxygen concentrations.
,3. A client is prescribed oxygen at 2 L/min by nasal cannula. What
approximate FiO₂ does the client receive?
A. 21%
B. 24%
C. 28%
D. 40%
Answer: C. 28%
Rationale: A nasal cannula generally increases FiO₂ by approximately 4% per
liter/minute. At 2 L/min, the estimated FiO₂ is about 28%.
4. Which oxygen-delivery device is most appropriate for a client who requires
a high concentration of oxygen but is breathing spontaneously?
A. Nasal cannula
B. Simple face mask
C. Nonrebreather mask
D. Venturi mask at 24%
Answer: C. Nonrebreather mask
Rationale: A nonrebreather mask can deliver a very high concentration of
oxygen, often approximately 60%–95%, when the reservoir bag remains
inflated and the mask fits properly.
5. The nurse applies a nonrebreather mask to a client. Which finding indicates
correct application?
A. The reservoir bag completely collapses during inspiration
B. The reservoir bag remains partially inflated during inspiration
C. Oxygen flow is set at 1 L/min
D. The exhaled air is directed into the reservoir bag
Answer: B. The reservoir bag remains partially inflated during inspiration
,Rationale: The reservoir bag should remain partially inflated during
inspiration to ensure the client receives the intended high oxygen
concentration.
6. Which oxygen flow rate is generally appropriate for a simple face mask?
A. 1–2 L/min
B. 3–4 L/min
C. 5–10 L/min
D. 15–20 L/min
Answer: C. 5–10 L/min
Rationale: A simple face mask should generally be used at 5–10 L/min. Lower
flows may allow carbon dioxide to accumulate inside the mask.
7. A client with chronic CO₂ retention requires controlled oxygen therapy.
Which device should the nurse anticipate?
A. Nonrebreather mask
B. Venturi mask
C. Partial rebreather mask
D. Face tent
Answer: B. Venturi mask
Rationale: A Venturi mask allows precise control of oxygen concentration,
making it useful for clients at risk for oxygen-induced hypercapnia, such as
some clients with COPD.
8. Before administering oxygen, what is the nurse's priority action?
A. Apply petroleum jelly to the client's nares
B. Assess the client's respiratory status
C. Place the client in a supine position
D. Increase the oxygen flow rate to 10 L/min
, Answer: B. Assess the client's respiratory status
Rationale: The nurse should assess respiratory rate, effort, breath sounds,
oxygen saturation, and overall clinical status before and during oxygen
therapy.
9. Which position usually promotes optimal lung expansion in a client
experiencing dyspnea?
A. Supine
B. Trendelenburg
C. High-Fowler's
D. Prone with legs elevated
Answer: C. High-Fowler's
Rationale: High-Fowler's positioning promotes diaphragmatic expansion and
reduces pressure from abdominal organs on the diaphragm, facilitating
ventilation.
10. Which instruction should the nurse give a client receiving oxygen at
home?
A. "Smoking is acceptable if you turn off the oxygen first."
B. "Keep oxygen equipment away from flames and heat sources."
C. "Use petroleum jelly inside your nose for dryness."
D. "Store oxygen cylinders next to a radiator."
Answer: B. "Keep oxygen equipment away from flames and heat sources."
Rationale: Oxygen supports combustion. Clients should avoid smoking, open
flames, sparks, and heat sources around oxygen equipment.
11. Which product should the nurse recommend for nasal dryness in a client
receiving oxygen?
